There are a lot of Flash physics engines available to use. I've only tried Box2D, APE, and Foam.
Foam is my favorite so far. I actually like the options of Box2D better but it's just not as ActionScript-friendly as Foam.

Foam sets up the easiest of these 3 engines for an ActionScript only project...In my opinion, setting it up to use in my Flex projects takes a little more work depending on what I use it for. Seeing the end result of it is fun to watch.

Below I'm currently using my polygon editor to test Foam out in Flex.

Here is a way to let a DisplayObject find the main WindowedApplication on its own...

In my AIR application I have other AIR Windows floating over the main AIR Window.
I wanted one of my UIComponents to be draggable like a cursor, but when my mouse dragged the object
over the other floating windows I wanted my original cursor to show again and hide my dragged UIComponent.

The reason behind this is if I wanted to apply "context sensitive" behaviors depending on what or which window the mouse is in.

To do this, the main WindowedApplication needed some ROLL_OUT and ROLL_OVER events added to it to detect when the mouse rolls in and out.
The "getAIRAppWindow" method below finds the main WindowedApplication so I can add the listeners to it from there.

Here are some snippets explaining what I did:

Read the rest of this entry »

Here is a Flex UI component I've been writing. Click the image to play with what I have made so far.
You can change a variety of properties. The dial and mark are runtime skinnable by setting its "dialBackgroundSkin" or "dialMarkSkin" property to a url with an image. 

Knobs and dials just look cool...I don't know anything about audio editing but I like the site of a sound studio. This is the "Reason" I decided to make a knob component.